A fuel pressure control valve is disclosed in DE-Al 40 10 173, which permits the use of plastic as a material for the housing of the valve. In contrast to known pressure control valves in which a cylindrical compression spring is arranged in a housing dome, the disclosed pressure control valve has a flat spring acting as a tension spring arranged in a fuel chamber. In order to adjust the control valve, a pipe connection forming a valve seat is screwed into the plastic housing, and the valve seat can be axially displaced by controlling the depth that the pipe connection is screwed into the housing.
Although this pressure control valve has a flat form, due to the use of the flat spring, for safety reasons, the use of plastic is viewed as unfavorable for the housing, since contact with fuel can change the properties of the plastic and the long-time behavior of the material can cause a loosening of the housing joint as well as the screw connection due to the fluctuating temperatures arising during engine operation.